Foam generating and dispensing device



1969 L. A. MICALLEF FOAM GENERATING AND DISPENSING DEVICE Filed June 7,1968 wlllllllllll IIIIIIIIII F/GI 2 I. 3 mm NJ 8 United States Patent 3471 064 FOAM GENERA'I'INGAND DISPENSING DEVICE Lewis A. Micallef, NewYork, N.Y., assignor to Leeds and Micallef, New York, N.Y., apartnership of New York Filed June 7, 1968, Ser. No. 735,433 Int. Cl.B65d 37/00, 83/00 U.S. Cl. 222-211 16 Claims ABSTRACT OF THE DISCLOSUREeither the bottle is agitated for purposes of wetting the tube so thatthe holes are covered by the liquid or, as will occur during normaloperation, the foam generated in the head space will serve to keep thetube wetted over prolonged periods. As the bottle is squeezed, air fromthe head space is forced through the holes in the tube whereupon the airmixes with the liquid disposed across the holes to form individualbubbles which collectively make up the desired foam. This foam continuesup the tube into the spout and out through its opening as the bottle issqueezed or compressed. Repeated squeezing of the bottle generates morefoam which eventually is dispensed out through the spout opening. Aftereach squeezing and when the bottle is released, air is sucked backthrough the spout into the tube and out through the tube opening intothe head space further foaming the liquid in the head space. This servesas a supplemental supply of the liquid to wet the tube for purposes ofgenerating more foam upon subsequent squeezing of the bottle.Maintaining the tube wet in this fashion or by tilting or agitating thebottle at periodic intervals will assure the continued generation offoam as the bottle is squeezed and then released.

Foams may generally be defined as a dispersion or suspension of finelydivided gas bubbles in a liquid. The individual gas bubbles areseparated from one another by a closed continuous thin film of theliquid. A foam, under these circumstances, will contain a relativelysmall but somewhat evenly distributed quantity of the liquid for arelatively large volume of foam. Under these circumstances, a relativelylarge surface area may be uniformly covered by foam so that a relativelysmall amount of the liquid is actually applied to this surface.

Accordingly, foams have many useful applications as a vehicle forindustrial, household, cosmetic and other personal application fields.Heretofore, foams or aerated products have experienced success asshaving creams, lotions, shampoos and detergents to mention a few. Inthese cases, the foam was generated and dispensed by means of an aerosoltype of container in which the foamable product was packed underpressure along with a suitable propellant and thereafter released in itsfoamable state through a valve controlled opening. However, severalinherent problems are necessarily present in the form of special fillingequipment as well as valves which increase the cost of the pressurepacked product. Not only is the cost of the propellant a contributingfactor but its chemical effect on the other constituents and containerwalls and valve must be taken into consideration.

3,471,064 Patented Oct. 7, 1969 ice It is, therefore, a principal objectof this invention to provide a relatively simple low-cost foam generatorwhich eliminates the disadvantages of the prior art while providing arelatively elficient foam producing technique.

Another object is to provide a foam generator of this type which Whilebeing capable of being refilled and reused, is sufficiently low in costto render it disposable after the foamable material has been consumed.

A further object is to provide a foam generator of the above type whichis capable of being filled and dispensed without requiring propellants,special filling equipment or valves and containers.

Other objects and advantages will become apparent from the followingdetailed description which is to be taken in conjunction with theaccompanying drawings in which:

FIG. 1 is a longitudinal sectional view through the foam generator ofthis invention showing the manual generation of foam by means of theinternally mounted perforated tube;

FIG. 2 is a similar longitudinal sectional view showing the foamgenerator after the squeezing operation has stopped and the Walls of thebottle or container have resumed their normal position showing themanner in which foam is thereby built up in the head space; and

FIG. 3 is a cross-sectional view taken along the line 33 of FIG. 2.

In the drawings, a typical squeeze-type of bottle 10 is shown and may beformed of conventional materials such as polyethylene, cellulose acetateand other suitable materials which permits squeezing of the bottles sidewalls 12 on the application of manual pressure and return to its initialsubstantially cylindrical shape upon release of this pressure. The top14 of the bottle 10 is provided with an opening 16 into the containerinterior and across which a spout 18 is sealed and secured. The spout 18includes the usual dispensing outlet 20 which may be closed by means ofa plug (not shown) during storage and shipping. Of course, a protectiveovercap of suitable form and construction may also be provided for suchpurposes. All of the caps of this type are well known in the trade.

A foam generating perforated tube 20 is mounted interiorly of the bottle10 and includes an opened upper end 22 fixedly mounted to a concentricsubstantially downwardly extending apron 24 of the spout 18. Under thesecircumstances, a direct conduit extends between the interior of the tube20 and the outlet 20 substantially as shown in FIG. 1. A plurality ofholes or openings 26 is provided in the side walls of the tube 20 over amajor portion of the upper part of the tube 20. These openings arerelatively small in size and may assume a circular or other geometricalconfiguration formed by punching or other production techniques. Optimumresults have been found to be achieved by closing the lower end 28 ofthe tube in a suitable fashion and by means of a plug or pinching andsealing as typified in the illustrated embodiment.

A successful commercial application of the present invention willinclude a filled bottle 10 with the selected foamable-material 30 to alevel at which a predetermined amount of head space 32 is provided. Inthis manner, the perforated part of the tube 20 is adapted to be wettedwith a relatively thin film of the foamable material 30. This wettingmay be accomplished by shaking or agitating the bottle 10 or merelytipping it to secure the desired wetting. In this connection, both theinner and outer face of the tube 20 will with repeated use contain afilm of the foamable product 30. In this connection, the mere squeezingof the side walls of the bottle 10 will force the foamable liquid 30upwardly to Wet a part of the tube 20. In addition, as foam is generatedand built up within the head space 32, the upper part of the tube 20will be constantly wetted. In addition, as foam is produced anddispensed, the unperforated part of the tube 20 which will have beenwetted will serve as a reservoir or supply for liquid which because ofthe liquid surface tension and dripping as a result of gravity willclose or extend across the perforated or pierced opening to permit onceagain the formation of more foam.

In order to produce a satisfactory foam, several factors must be takeninto consideration including the number and size of openings 26, thesize of the inner bore of the tube 20, the nature and level of thefoamable product and the size and shape of the bottle otherwiseexcessive air will exit from the spout opening or excessive product willbe discharged therefrom which in the extreme would be unaerated orunfoamed liquid 30. Of particular interest is that when all of thefactors are balanced properly, foam will be generated whether the bottle10 is being squeezed or is recovering; and in the latter case, the foambuilds up on the outside of the tube 20 in the head space 32. Withinthat portion of the tube 20 adjacent the tube lower end 28, a foamableliquid reservoir is provided which after repeated use will become filledwith nonaerated product which is utilized for wetting the inside of thetube 20.

In actual use, the bottle is squeezed and released, foam is formed onboth the inside and outside of the tube 20. The light foam in the headspace breaks down slowly and as it mixes with the new form that iscreated when the bottle is squeezed, upgrades the quality of the finalproduct by producing a finer grained and drier foam. During the decreaseof the cross-sectional area of the bottle incident to squeezing, thelevel of the product 30 will be raised, covering some of theperforations 26, this does not detract from the effectiveness of thegenerator since it is producing foam during the time the bottle isinitially squeezed and by the time the liquid 30 reaches the level whereit could effect the balance of air to liquid within the bottle 10, butat this juncture, the limit to which the bottle 10 can be squeezed hasgenerally been reached. In this connection, cylindrical bottles arepreferred because they have the maximum displacement potential; and insuch cases, the bottles were filled to between two-thirds andthree-quarters capacity.

It should be understood by optimum foam is meant the quality of the foamwhich should be dry and substantially long lasting, the need for minimumconsumer instruction and the lessening of restrictions as to the typeand size of squeeze bottles employed.

It has been found that in order to successfully practice the presentinvention, the internal diameter of the tube 20 should be in the orderof one-quarter of an inch with a nominal diameter being of the order offive-sixteenths of an inch. With respect to the diameter of the tube 20,the controlling factor is the availability of enough surface area toaccommodate the number of holes 26 which, when present, will produce theoptimum foam. In this connection, the reduced size holes 26 permits theproduction of a venturi action which, together with the surface tensionof the foamable liquid, results in the formation of quality foam.

With respect to the number of holes 26 provided in the tube 20, aminimum of about 400 and a maximum of about 1,000 is suggested with arange of between 750 and 950 being preferred. With respect to thearrangement of holes 26, it is found that in a convenientcounter-balanced arrangement down the length of the tube to a depth ofabout one-half to three-quarters of the tubes total length as workedsatisfactorily. In this connection, a balanced arrangement is intendedto mean an even distribution of holes about the periphery of the tube20. A greater concentration of holes in the upper end of the tube 20,will raise the ratio of air to product, a greater concentration of holesnear the lower end of the perforated part of the tube will raise theratio of product to air. The diameter of the holes 26 should be from.005 inch to .0l5iinch with .010 inch being preferred. Holes of thismagnitude with the foamable products contemplated tend to hold the filmacross the openings while cooperating to maintain a slight increase inthe velocity of fluid movement which is felt in the form of a slightresistance as the bottle 10 is manually squeezed.

With respect to the tube 20 of the illustrated embodiment in which thelower end 28 is closed, the number of holes 26 of a diameter of .010inch does not noticeably improve the quality of the foam as the numberis in creased above the maximum limit defined in the above. The size ofthe openings 26, as aforenoted, should take advantage of the naturalsurface tension of the film of foamable product that is formed on theinner and outer surface of the tube 20. A lesser number of holes thanthe minimum mentioned in the above will produce a foam, but the problemcreated is in the ability of the bottle 10 to recover when squeezing andrelease of manual pressure has stopped. The holes 26 will, in effect,operate as a brake offering resistance to the passage of air from theambient back into the bottle head space. Thus, the number of holes has adirect bearing on the speed at which the bottle recovers its shape afterit has been squeezed. A minimum of 400 holes permits the bottle torecover in an acceptable fashion. As the number of holes is increasedabove 400, the quality of the foam improves, at about 900 there is alevelling off until about 1,000 holes. At this point, the ratio of airto product begins to increase sufficiently so as to cause the quality ofthe foam to deteriorate.

The general rule in determining the number of holes is that theaggregate value should allow for a slight resistance to fluid flow asthe bottle is squeezed. Of course, the internal diameter of the tube 20should define an internal cross-sectional area of the tube whichapproaches the aggregate open area provided by the openings 26. Forexample, the aggregate area of 800 holes 26- having a diameter of .010is approximately .06 inch whereas a tube with a five-sixteenths inchinternal bore has an area of about .08 inch which is well within thebroad comparative analysis where velocity of product through the holes26 and out through the spout opening 20 matches the aerating ability ofthe holes 26. This range has been found to be about 20 percent. As thediameter of the holes 26 increase beyond the maximum limit, a leak is ineffect provided whereupon a greater volume of combined air within thehead space will be expelled upon squeezing of the bottle 10. Thisleakage phenomenon is particularly noticeable when the bottom end 28 ofthe tube 20 is opened. As stated in the foregoing, it is preferred thatthis bottom end he closed for optimum results. It should be understoodthat if the holes 26 were arranged on the entire length of the tube 20,they would offset the effect of this sealed lower end 28 which is topreclude raw foamable product 30 from rising in the tube 20 as thebottle is squeezed. It has been found that with a tube 20"having an openlower end 28 there is the danger of raw product 30 being dispensed upthrough the tube and out of the outlet 20 particularly if the bottle 10is squeezed too hard and too rapidly. Under these circumstances, it ispreferred that the lower end of the tube 20 be sealed and the holes 26extend across only about one-half of the tube length.

In selecting the tube 20, its wall thickness is important. It ispreferred that this thickness be held at a minimum and a thickness ofone thirty-second of an inch has been found to perform satisfactorily.In this connection, the least expensive and fastest way of making alarge number of small diameter holes 26 is to execute a piercingoperation. Since a clean cut hole is not essential, a sharp point of theproper diameter is all that is required. Punching these holes wouldrequire a male and female die with a greater risk of tool breakage andthe problem of disposing of the punched out slugs. A thin tube wallfacilitates piercing with a needle or the like and, at the same time,permits the points to be kept relatively short thereby reducing thepossibility of breakage.

The present invention contemplates several alternative embodiments orsupplementation of the basic contribution to the foam generating art. Inthis connection, a wick-like arrangement may extend around theperforated tube to insure wetting of the tube and offsetting therequirement for agitation in one form or another for purposes of wettingthe tube. Accordingly, an absorbent material may be employed forenclosing the tube within the bottle but which will permit passage ofair therethrough. This material may be in the form of a perforated papercloth or the like capable of acting as a wick which constantly keeps thesurface of the tube 20- damp or wet.

Furthermore, the pierced tube 20 of suitable resinous material andalthough preferred could be replaced by a fine mesh screen which couldbe rolled into a tube. A limiting factor with the use of a fine meshscreen is that the number of holes in a given area will be fixed whereaswith a tube of the type contemplated, the number of holes pierced can bevaried according to the particular requirements and specifications. Ofcourse, with the use of a fine mesh screen, a coating or laminate can beemployed to close off that part of the screen that would be undesired ornot necessary. With this approach, the cost of the finished productwould necessarily be increased. Similarly, a coating of inert materialwill generally be required for the screen to prevent or minimize anyinteraction between the screen material and the foamable liquid 30.Flocking of one form or another can be employed for such purposes andone advantage of this is that it would serve as an absorbent for keepingthe tube wet.

In addition, a binary or multiple tube arrangement is envisioned inwhich one or more of the tubes is pierced in accordance with thepreferred embodiment and one or more of the other tub'es arranged inconcentric relationship would serve as wicks or capillary channels fortaking up and holding the foamable product 30 and, in this manner,keeping the pierced tubes wet for purposes of generating foam andminimizing the requirements for bottle agitation.

It will be appreciated by those skilled in the art that when thesqueezing pressure on the bottle 10 is released, a non-drip type ofdispenser is provided in which the product that is not consumed at thedischarge opening 20 and within the spout 18 is withdrawn back into thetube 20 and container 10. An attractive aspect of the present inventionis the self-purging effect produced when the bottle is released whichwill in actual practice tend to maintain the spout 18 and its dischargeopening 20 clear and the foam or bubble producing openings 26essentially non-plugged and cleared for purposes of producing qualityfoam. This cleaning and self-purging is further enhanced by agitation ofthe bottle for purposes of keeping the tube 20 wet and, in this manner,essentially clean.

Thu-s, the several aforenoted objects and advantages are mosteffectively attained. Although several somewhat preferred embodimentshave been disclosed and described in detail herein, it should beunderstood that the invention is in no sense limited thereby and thescope is to be determined by the appended claims.

I claim:

1. A device for producing and dispensing foam comprising in combination:a hollow container means adapted to contain a foamable liquid in anon-foaming state, said container means being of flexible material andcapable of being compressed so as to have its volume reduced and capableof being self-expanding back to its original volume, said containermeans having an upper open end, a dispensing outlet means mounted on theupper open end of the container means for directing the foam to bedispensed to the selected location, a tube mounted interiorly of thecontainer means and having an open upper end communicating with thedispensing means for passage of the foam from the tube into thedispensing means, the

tube having a longitudinally extending tubular side wall defining aninternal bore extending to and communicating with the tube upper end,the tube side wall having a plurality of openings communicating with theinterior of the container means and the bore of the tube, the openingsin the tube side wall being capable of being covered by the foamableliquid in its non-foaming state whereupon compression of the containermeans generates foam in the tube bore which is adapted to be ultimatelyforced upwardly out through the tube upper opening into and eventuallyout of the dispensing means.

2. The invention in accordance with claim 1 wherein the tube side wallopenings are disposed along a major part of the upper end of the tube.

3. The invention in accordance with claim 1 wherein the tube is providedwith sealing means at its lower end for sealing the tube bore at thetube lower end.

4. The invention in accordance with claim 1 wherein the container meansis adapted to expand back to its original volume upon removal of thecompressive forces whereupon foam is generated in the head space withinthe container means above the level of the foamable liquid to therebymaintain the upper surfaces of the tube side walls wet with the foamableliquid and provide for a reserve of the foam for dispensing uponsubsequent compression of the container means.

5. The invention in accordance with claim 1 wherein the container meansis substantially circular in section over the major portion of itslength.

6. The invention in accordance with claim 1 wherein the side wallopenings of the tube are dispersed substantially uniformly about theperiphery of at least the upper portion of the tube.

7. The invention in accordance with claim 1 wherein the openings in thetube are pierced.

8. The invention in accordance with claim 1 wherein the openings extendapproximately over one-half of the length of the tube.

9. The invention in accordance with claim 1 wherein the number of holesor openings is between 400 and 1,000.

10. The invention in accordance with claim 1 wherein the number of holesor openings is between 750 and 950.

11. The invention in accordance with claim 1 wherein the internaldiameter of the tube is about one-quarter of an inch.

12. The invention in accordance with claim 1 wherein the internaldiameter of the tube is approximately fivesixteenths of an inch.

13. The invention in accordance with claim 1 wherein the size of thetube openings is between .005 inch to .015 inch.

14. The invention in accordance with claim 1 wherein the diameter of thetube openings is approximately .010 inch.

15. The invention in accordance with claim 1 wherein the lower end ofthe tube is closed.

16. The invention in accordance with claim 1 wherein the tube has a wallthickness no greater than one-thirtysecond of an inch.

References Cited UNITED STATES PATENTS 1,991,720 2/1935 Barreda et al.222-464 3,260,421 7/ 196 6 Rabussier 222464 X 3,346,146 10/ 1967Thompson 222- X 3,409,181 11/ 1968 McDonnell 22--213 X ROBERT B. REEVES,Primary Examiner NORMAN L. STACK, 1a., Assistant Examiner US. Cl. X.R.222-190

